A conventional electrical connector, shown in FIGS. 9 and 10 (see Japanese Patent No. 3101203), comprises a retainer that is inserted from the front surface of the housing, i.e., a so-called front insertion type retainer.
This electrical connector 101 shown in FIGS. 9 and 10 comprises an insulating housing 110, a plurality of contacts 120 that are accommodated in the housing 110, and a retainer 130 that is inserted from the front surface of the housing 110 and that double-locks the contacts 120.
A plurality of contact accommodating cavities 111 for accommodating the contacts 120 are formed inside the housing 110 in two rows (upper and lower rows). A housing lance 112 for locking the corresponding contact 120 is disposed inside each contact accommodating cavity 111. Furthermore, protruding wall parts 113 that respectively protrude upward and downward from the top wall and bottom wall of the housing 110 are present on the left and right side walls of the housing 110, and temporary locking steps 114 are formed substantially in the central part in the forward-rearward direction (i.e., substantially in the central part in the left-right direction in FIG. 10) of the respective protruding wall parts 113. Moreover, main locking holes 115 are respectively formed in the rear portions of the top wall and bottom wall of the housing 110. In addition, a partition wall 116 that divides the contact accommodating cavities 111 of the upper and lower rows is formed between these contact accommodating cavities 111 of the upper and lower rows, and a V groove 117 is formed in the front end of this partition wall 116.
Each contact 120 comprises a substantially box-shaped receptacle part 121 that is secured by the corresponding housing lance 112, and an electrical wire connecting part 122 that extends rearward from the receptacle part 121 and that is connected by crimping to one of the electrical wires W.
The retainer 130 is constructed so that this retainer is inserted into the housing 110 from the front surface of the housing 110, and is locked to the housing 110 in a temporary locking position that allows the insertion of the contacts 120 into the contact accommodating cavities 111 and in a main locking position that double-locks the contacts 120. The retainer 130 comprises a rectangular substantially flat front plate 131 that extends in the direction of length (left-right direction in FIG. 9) so as to cover the front surface of the housing 110, and a plurality of locking arms 133 and 134 that respectively extend rearward from the areas in the vicinity of the upper and lower ends of the front plate 131. The retainer 130 is formed by molding an insulating synthetic resin. A plurality of contact passage holes 132 are formed in the front plate 131 in positions corresponding to the contact accommodating cavities 111. Furthermore, temporary locking projections 133a are formed so that these projections 133a protrude from the side edges on the outside of the respective upper-side locking arms 133 in positions located slightly toward the rear (in the forward-rearward direction) of the respective locking arms 133, and main locking projections 133b are formed so that these projections 133b protrude from the top surfaces on the rear ends of the respective locking arms 133. Moreover, temporary locking projections 134a are formed so that these projections 134a protrude from the side edges on the outside of the lower-side locking arms 134 in positions located slightly toward the rear (in the forward-rearward direction) of the respective locking arms 134, and main locking projections 134b are formed so that these projections 134b protrude from the bottom surfaces on the rear ends of the respective locking arms 133. A plurality of supporting parts 135 that extend in the direction of length are formed so that these supporting parts 135 protrude rearward from the center on the side of the back surface of the front plate 131. The rear ends of the respective supporting parts 135 are formed in a V shape.
When the retainer 130 is in the temporary locking position, the temporary locking projections 133a and 134a of the retainer 130 are locked on the rear sides of the temporary locking steps 114 of the housing 110, so that the retainer 130 is prevented from slipping out of the housing 110. Moreover, when the retainer 130 is in the main locking position, as is shown in FIG. 10, the main locking projections 133b and 134b of the retainer 130 are locked in the main locking holes 115 in the housing 110, so that the retainer 130 is prevented from slipping out of the housing 110. In this main locking position, the upper-side locking arms 133 of the retainer 130 are positioned above the housing lances 112, and restrict the upward movement of the housing lances 112, thus accomplishing the double-locking of the contacts 110 of the upper row. Furthermore, the lower-side locking arms 134 of the retainer 130 are positioned beneath the housing lances 112, and restrict the downward movement of the housing lances 112, thus accomplishing the double-locking of the contacts 110 of the lower row. Moreover, in the main locking position of the retainer 130, as is shown in FIG. 10, portions of the rear ends of the supporting parts 135 enter into the V groove 117 of the housing 110, and thus stop movement of the retainer 130 in the vertical direction caused by looseness; furthermore, these portions of the supporting parts 135 also prevent the second locking arms 118 of the housing 110 that lock the contacts 120 from flexing inward.
However, the following problems have been encountered in this conventional electrical connector 101.
Specifically, by providing the supporting parts 135 that protrude rearward from the back surface of the front plate 131 of the retainer 130, backlash of the retainer 130 at the time of main locking can be stopped, and the rigidity of the front plate 131 of the retainer 130 can be increased. However, these supporting parts 135 protrude to the rear in a relatively thick state. Accordingly, the dimensional stability of the retainer 130 is poor in a state in which the retainer 130 is molded. Moreover, the warpage of the locking arms 133 and 134 that extend from the areas in the vicinity of the upper and lower ends of the front plate 131 of the retainer 130 cannot be avoided.